500 likes | 613 Views
FTTx Architectures and Why it Matters for the Open Access Debate. Marvin A. Sirbu Department of Engineering and Public Policy Carnegie Mellon University sirbu@cmu.edu http://www.andrew.cmu.edu/user/sirbu/. Conclusions Up Front. FTTP networks have significant economies of scale
E N D
FTTx Architectures and Why it Matters for the Open Access Debate Marvin A. Sirbu Department of Engineering and Public Policy Carnegie Mellon University sirbu@cmu.edu http://www.andrew.cmu.edu/user/sirbu/
Conclusions Up Front • FTTP networks have significant economies of scale • facilities-based competition is unlikely to be sustainable • Service-level competition can exist over shared network infrastructure • Sharing possible at different levels • Sharing of dark fiber requires attention to fiber layout • There is great variety in the models of sharing which can be found today • A wholesale-only provider is financially viable • It is not necessary to be vertically integrated to be profitable
Outline • Models of Competition in FTTP • Alternative FTTP architectures: impact on competition • Economics of FTTP • Economics of a Wholesale/Retail split
Outline • Models of Competition in FTTP • Alternative FTTP architectures: impact on competition • Economics of FTTP • Economics of a Wholesale/Retail split
Facilities based competition – each competitor builds FTTP network
UNE (LLU) based Competition in FTTP • Dark fiber based – network owner wholesales dark fiber • Wavelength based – network owner wholesales wavelengths
Open Access based competition – network owner wholesales transport capacity
Examples of Sharing at Different Layers 0 Open access to ducts • Portugal • France • Dark fiber at layer 1 • Stokab in Stockholm • VLAN service at layer 2 • UTOPIA • Amsterdam • Pau
Multiple Layer Separation Amsterdam Source: http://www.citynet.nl/upload/Wholesale-bandwidth-Amsterdam-Citynet.pdf
Issues and Problems • If you build a wholesale network, will there be service providers? • Kutztown, PA wanted to do only up to layer 2 and couldn’t find service providers to run over the network • Operations finger pointing between wholesaler and retailer • Provo Utah sold its layer 2 wholesale network to a service retailer arguing that integrated operations are cheaper • Economies of scale • Operating company to light the fiber in multiple cities • Axione • Packet Front
Outline • Models of Competition in FTTP • Alternative FTTP architectures: impact on competition • Economics of FTTP • Economics of a Wholesale/Retail split
Home Run Architecture • Implications for Competition • Physical layer unbundling possible – wholesaler can sell individual fiber • Also supports open access
Active Star Architecture • Implications for Competition • Physical layer unbundling is difficult • requires competitors to collocate electronics at remote node • Must provide feeder fibers for each competitor • Logical layer unbundling possible - supports open access
Curb side Passive Star Architecture (PON) • Implications for Competition • Physical layer unbundling not possible • Logical layer unbundling possible - supports open access Separate λ’s may be used for Data and video
WDM PON • Implications for Competition • Physical layer unbundling not possible • Optical layer unbundling possible – wholesaler can sell wavelengths • Also supports open access
Design Considerations in a PON: A Curb-side PON • Both OLTs needed if only one home in each splitter group subscribes
Design Considerations in a PON: A Fiber Aggregation Point (FAP) PON • Fiber Aggregation Point PON supports all models of competition
How many homes should be aggregated at an Optimal FAP? • OFAP allows deferring investment in OLTs until penetration requires it
OFAP as a Real Option to Phase-in New Technologies • OFAP also supports flexibility • in future split ratios - 10 Gbps GPON, GEPON - WDM PONs
OFAP Benefits withan Active Star Architecture RT & OLT tobe deployed as needed • Higher utilization of RT and OLT ports • Neighboring homes can be served by different technology generations • Larger serving area
Sharing in the “Second Mile” • As video becomes dominated by unicast Video on Demand (VOD) metro aggregation network costs soar • In smaller communities, access to regional transport to a Tier 1 ISP is a major barrier to entry • Retail service providers sharing an FTTH access network may also need to share at the metro/regional level in order to be economically viable. • NOAAnet • There is a tradeoff with distributed video servers • Sharing a content delivery network (e.g. Akamai) may be an alternative. • This requires distributed colo space and interconnection • See Han, S. et al “IPTV Transport Architecture Alternatives and Economic Considerations,” IEEE Comm Mag, Feb 2008 • Lamb L., “The Future of FTTH – Matching Technology to the Market in the Central Office and Metro Network,” NOC 2008. • NSP, “A Business Case Comparison of Carrier Ethernet Designs for Triple Play Networks,”
Regulatory Implications • If regulators want to be able to require dark fiber unbundling, they need to require compatible fiber layout • OFAP PON vs curb-side PON • Even larger OFAP for competitive active star • Need for additional feeder fibers for competitors • All architectures support logical layer (“bitstream”) unbundling • IPTV unbundling possible at bitstream layer • If video distributed over a separate wavelength, issues of access to RF multiplex.
Outline • Models of Competition in FTTP • Alternative FTTP architectures: impact on competition • Economics of FTTP • Economics of a Wholesale/Retail split
Simple FTTH Economics: FTTH Includes Fixed Plus Variable Costs Cost = Fixed + R * Variable $ • e.g. for Verizon YE06 • Fixed=$850 • Variable=$880 Source: http://investor.verizon.com/news/20060927/20060927.pdf Slope = avg cost Fixed costs 0% 100% Take Rate (R = customers / homes passed) Adapted from Friogo, et.al. http://ieeexplore.ieee.org/iel5/35/29269/01321382.pdf
How Much Revenue to Support FTTH? • One operator estimates $90/month per subscriber • $40 for ongoing services cost • $50/month to cover capital costs • Assume an average of 10 year lifetime, 5% cost of capital • Fiber lasts 40 years • Electronics lasts five years • $50/month can amortize $4700 • What if Average Revenue Per User (ARPU) is less? • $30/month can amortize $2800
Cost Per Subscriber vs Take Rate Percent take rate needed to break even Capital that can be amortized with $50/mo/sub Capital at $30/mo/sub Adapted from Frigo et. al.
Cost Per Subscriber vs Take Rate Take Rate Consumers Capital that can be amortized with $50/mo/sub Competition Adapted from Frigo et. al.
Economic Implications: • If revenue available to amortize plant is only $30/month, must reach penetration of > 45% • room for at most 2 facilities-based providers • This analysis understates the problem • No customer acquisition (marketing/sales) cost included • Customer acquisition drives up Fixed costs pushing breakeven penetration higher • Unlikely to see >90% total penetration
Regulatory Implications • Facilities-based competition among fiber network providers is unlikely • Economies of scale • Regulators should be cautious of waiving open access requirements in return for investment in fiber • Could lead to remonopolization • At best duopoly competition • If service competition limited to ISPs which own facilities greatly reduced service level competition • Operators will have Significant Market Power (SMP) • Reduced service-level competition raises Network Neutrality issue
Net Neutrality • Can third parties compete with vertically Integrated ISPs? Apps + Con- tent Apps + Con- tent Apps + Con- tent
Outline • Models of Competition in FTTP • Alternative FTTP architectures: impact on competition • Economics of FTTP • Economics of a Wholesale/Retail split
Economic Analysis: Motivating Question • Open Access: Network operator provides wholesale transport to service providers • Do sustainable prices exist for an infrastructure-only provider? • Build a supply/demand model and calculate welfare effects for different industry structure models
Structural separation interferes with the ability to price discriminate • Does this make a wholesaler less likely to recover costs vis-à-vis a vertically integrated entity? • Vertically integrated entity • Can sell 7 bundles: Voice, Data, Video, Voice-Data, Voice-Video, Data-Video, Voice-Video-Data • Can set 7 prices • Dark fiber wholesaler • Can sell only dark fiber access • Can set only one price
Wholesale Prices and Arbitrage • A dark fiber wholesaler can set only one price • A lit fiber wholesaler can set a price for data or video bandwidth but cannot set a separate price for the bundle • Video bandwidth is sufficient to offer both video and data services to customers, so • Wholesale price of “bundle” bandwidth and “video” bandwidth must be the same
Single Service Provider 2-service • Duopoly 2-service • Single Service provider 3-service We have studied 3 models Assumptions • FTTP network only network serving market • Voice services are provided over a separate network • FTTP network used to provide only data and video services • FTTP network only network serving market • FTTP network used to provide voice, video and data service • Market already served by (cable) incumbent when FTTP provider enters • FTTP and incumbent network used to provide only data and video services
Two-service model for the Wholesale-Retail Split • Demand Model • Consumers have different willingness to pay for voice, video and data services: Willingness to pay for a particular service can be modeled by a statistical distribution for a particular market • There is correlation between the willingness to pay for voice, video and data for one particular consumer: One can imagine a 3-space where the coordinates of each point give her willingness to pay for voice, video and data services • For simplicity, here we assume everyone wants voice – so our demand model is 2-space, where the coordinates of each point give the willingness to pay for data and video
Demand Model.. A Z P3 P2 C B D P3 P1 X1=Homes taking service1 (data) at price P1 (Area BDP1P3)X2=Homes taking service2 (video) at price P2 (Area ACP2P3)X3=Homes taking service3 (video and data) at price P3 (Area ACDBZ)
Supply Model • Annualized Fixed cost for wiring up the entire market consisting of X homes = F • Annualized Fixed Cost of installing CPE and drop loop = C0 • Annual incremental cost of providing data service (Service 1) per home = C1 • Annual incremental cost of providing video service (Service 2) per home = C2 • Observation: Marginal Cost of Bundle (C0 +C1+C2) is less than the sum of Marginal Cost of Data (C0 +C1) and Marginal Cost of Video(C0 +C2) • If X1 homes take data service, X2 homes take video service and X3 take both, annual cost of providing service = F + C0(X1+X2+X3)+ C1X1+ C2X2+ (C1+C2)X3
Possible Industry Structures • Vertically Integrated entity (Network owner provides retail service) • ‘Verizon’ Model (Profit Maximizing) • ‘Bristol’ Model (Welfare Maximizing) • Structurally Separated entities (Network owner, either by regulation or choice, is only a wholesaler. The retail market is assumed to be competitive/contestable) • ‘Grant County Profit (GCP)’ (Profit Maximizing layer 2 service wholesaler) • ‘Grant County Welfare (GCW)’ (Welfare Maximizing layer 2 service wholesaler) • ‘Stockholm Profit (SP)’ Model (Profit Maximizing dark fiber wholesaler) • ‘Stockholm Welfare (SW)’ Model (Welfare Maximizing dark fiber wholesaler)
Model Results • Not surprisingly, if network owner optimizes Social Welfare (e.g. Bristol) consumers are much better off than if network owner optimizes profit • If network owner optimizes profit, THERE IS VIRTUALLY NO DIFFERENCEin profit for a vertically integrated firm or a wholesaler. • The fact that vertically integrated firm has more flexibility to price discriminate is not important since most households subscribe to the bundle, and wholesaler can extract the same rent. • Ifthere is a large fraction of the population with no interest in broadband data, then vertically integrated firm can do 25% better than a dark fiber wholesaler, but still no better than a lit fiber wholesaler.
3 services model shows less than 5% difference Stockholm and Verizon profits F=5x104 C0=8 C1=20 C2=30 C3=5 1= 35 σ1= 10 2 = 45 σ2 = 10 3= 25 σ3= 10
Similar profits are attained in spite of a different distribution of subscribers
What if There Are Competing FTTP Operators? • If services are identical, classic case of natural monopoly • Firm with higher penetration has lower costs • Ruinous competition • Having sunk cost in fixed plant, each competitor is willing to price at marginal cost • negative profits • Stable competition can exist only if there are • Differentiated services appealing to heterogeneous customer tastes; or • High switching costs
Duopoly Model Results • We assume two operators with similar cost structures, one an incumbent, one a new entrant • Assuming video and data services are sufficiently differentiated between competitors, both can survive in the marketplace • If the new entrant is a wholesaler only, or vertically integrated makes no difference in its profit • An incumbent competing against a dark fiber wholesaler is modestly worse off than when competing against a vertically integrated competitor • Wholesaler’s inability to price discriminate forces competitor to reduce price discrimination and lose profit.
Model assumptions and caveats • Retail industry assumed to be perfectly competitive and no entry barriers; retailers make zero economic profit • Revenues derived entirely from end customers, not from application service providers • No economies of scope at retail assumed • Incremental costs, Ci , are the same in both vertically integrated and competitive retail cases • Competition should drive down incremental costs of services • Layer 2 costs, C0, are the same whether supplied competitively or by wholesaler • See above
Regulatory Policy Implications • Operators, municipalities or communities that build out FTTP and choose to be wholesalers: • (i) can realize sustainable prices, • (ii) are likely to create greater welfare (due to innovation spurred by retail competition) and • (iii) are just as likely to recover costs (vis-à-vis vertically integrated entities) • Model results contradict claims by operators that vertical integration is necessary to support investment in FTTP infrastructure regulatory holiday for FTTP investment is unwarranted.
Conclusion • What are the different models of competition in FTTP? • Facilities based • Service level (over shared network infrastructure) • Fiber layout affects options for competition • OFAP supports fiber unbundling even for PONs • More feeder fibers required for competition • FTTP networks have significant economies of scale • Unlikely to support multiple facilities-based providers • “Second Mile” sharing also important • A Wholesale Operator can earn profits similar to those available to vertically integrated competitors • It is not necessary to be vertically integrated in order to “earn enough” to pay for the infrastructure
For Further Information • http://www.andrew.cmu.edu/user/sirbu/pubs/Banerjee_Sirbu.pdf • http://web.si.umich.edu/tprc/papers/2006/648/Banerjee_Sirbu%20TPRC_2006.pdf • http://cfp.mit.edu/groups/broadband/muni_bb_pp.html